Added image compression plugin.

config/default.yml

@@ -43,6 +43,8 @@ cache:
     enabled: true
     limit: 2000
 
+imgcompression:
+  enabled: true
 
 gzip:
   # Compression level for gzip.
@@ -50,4 +52,4 @@ gzip:
 
 # Block gif2video by default
 gif2video:
-  enabled: false
+  enabled: false

lib/plugins/imgcompression.js

@@ -0,0 +1,71 @@
+var fs = require('fs');
+var temp = require ('temp');
+var execFile = require('child_process').execFile;
+var mozjpeg = require('mozjpeg').path;
+var pngquant = require('pngquant-bin').path;
+var imgtype = require('imagetype');
+
+exports.name = 'imgcompression';
+
+exports.handleResponse = function(request, source, dest) {
+  // If this is an image we first write it into a file, then optimize it
+  // and send it
+  if (source.headers['content-type'] === 'image/jpeg' ||
+      source.headers['content-type'] === 'image/png') {
+    var path = temp.path();
+    var optPath = path + '.opt';
+    var imageFile = fs.createWriteStream(path);
+
+    source.pipe(imageFile);
+
+    imageFile.on('finish', function() {
+      function sendImage(path) {
+        fs.stat(path, function(err, stats) {
+          dest.headers['content-length'] = stats.size.toString();
+
+          imageFile = fs.createReadStream(path);
+          imageFile.pipe(dest);
+
+          dest.on('end', function() {
+            fs.unlink(path);
+          });
+        });
+      }
+
+      // We need to check the actual type of the downloaded image.
+      // Some websites (e.g. mozilla.org) are sending JPEGs as PNGs.
+      imgtype(path, function(type) {
+        if (type === 'png') {
+          execFile(pngquant,
+                   ['--skip-if-larger', '-o', optPath, path],
+                   function(err) {
+                     if (err) {
+                       sendImage(path);
+                     } else {
+                       sendImage(optPath);
+                       fs.unlink(path);
+                     }
+                   });
+        } else if (type === 'jpeg') {
+          execFile(mozjpeg,
+                   ['-outfile', optPath, path],
+                   function(err, stdout, stderr) {
+                     if (err) {
+                       console.log('error:', stderr);
+                       sendImage(path);
+                     } else {
+                       sendImage(optPath);
+                       fs.unlink(path);
+                     }
+                   });
+        } else {
+          sendImage(path);
+        }
+      });
+    });
+  } else {
+    source.pipe(dest);
+  }
+
+  source.resume();
+};

lib/plugins/plugins.yaml

@@ -5,4 +5,4 @@ request:
 # Response plugins go here, and the response pipeline is
 # constructed in the order given
 response:
-  [ingress, gunzip, dom/gif2video, dom, gzip, cachesave, egress]
+  [ingress, imgcompression, gunzip, dom/gif2video, dom, gzip, cachesave, egress]

package.json

@@ -16,23 +16,28 @@
     "proxy"
   ],
   "author": "Eugen Sawin <esawin@mozilla.com>",
+  "contributors":  [ "Sylvain Cleymans <sylvain.cleymans@gmail.com>" ],
   "license": "MIT",
   "dependencies": {
+    "cheerio": "0.15.0",
     "config": "^0.4.36",
+    "follow-redirects": "0.0.3",
     "hiredis": "^0.1.17",
+    "imagetype": "^0.2.0",
     "js-yaml": "^3.0.2",
     "memory-cache": "0.0.5",
+    "mozjpeg": "^0.1.2",
+    "optimist": "~0.6.1",
     "png": "~3.0.3",
+    "pngquant-bin": "^0.3.1",
     "redis": "^0.10.3",
     "spdy": "~1.26.0",
     "synchronize": "^0.9.3",
-    "cheerio": "0.15.0",
-    "temp": "^0.7.0",
-    "js-yaml": "^3.0.2",
-    "follow-redirects": "0.0.3"
+    "temp": "^0.7.0"
   },
   "devDependencies": {
     "jscs": "^1.4.5",
     "jshint": "^2.5.1"
   }
 }
+